Eastside neighbors near the Highway 520 expansion say state transportation managers are giving them the runaround over a roundabout.

There’s little chance now that opponents can disrupt the plan for a big rotary interchange at 92nd Avenue Northeast, the entrance to tiny Yarrow Point. Public process has been under way for years. Final design is complete. Construction teams are building a giant freeway lid next to the site of the one-lane roundabout.

But some residents, including the town’s mayor, say it still should be possible to revert to a simpler version, like the T-shaped junction that existed for 50 years.

The planned layout — some 120 feet in diameter with roads from five directions — exemplifies how the state is overengineering and overspending on its projects, resident Chuck Hirsch said.

“Until it’s built, we see no reason why it has to be built,” Hirsch said.

In fact, the state Department of Transportation (DOT) was willing to scrap the roundabout two years ago, after receiving 450 signatures. The state offered a plain T instead, if Yarrow Point paid $900,000 to cover what transportation officials said were re-engineering costs and recruited support from other towns.

The town said it didn’t have the money. The controversy faded.

What this proves, both sides agree, is that a roundabout isn’t essential for handling traffic demand.

At this point, the state’s main concern is staying on schedule, said Julie Meredith, 520 project manager. Planning for a new Highway 520 floating bridge and approach lanes, to cost more than $4 billion, has been under way since 1997.

“At this point, we are close to the end of construction,” she said, of the Eastside section. The segment from Interstate 405 to the lakeshore was to be done this December, but delays pushed the timeline to June 2014. And the $306 million contract just for the Eastside part is expected to reach up to $395 million because of change orders and delays.

Several years ago, the town accepted the roundabout, along with the rest of the design. State officials say a roundabout in Yarrow Point reduces the conflict points where stopped traffic enters moving traffic — everybody passes through at 20 mph or so.

Neighbors thought it would be similar to the landscaped circle in Hunts Point or hundreds in Seattle neighborhoods, said Dicker Cahill, mayor for the town of 1,015 residents. It’s only in the last two years, when contractors carved a wider roadbed for the whole six-lane highway, that residents understood the impact, he said. The diameter is as long as two Metro buses.

“When the trees came down, we woke up,” Cahill said.

‘Egg-about’

Roundabouts are proliferating in Washington state, which now has about 120 in just about every region except Seattle city limits. A pair worth $7.7 million just opened on Highway 92 in Lake Stevens, where the state had reported 42 collisions from 2006 to 2010.

They are designed to improve safety. Roundabouts remove the risk of side and rear-end crashes in a traditional crossing, where some cars stop while others cross at 30 to 50 mph.

The five-legged Yarrow Point roundabout looks like a starfish. Of the five roads, four are split by small triangular medians near the starfish’s torso, to give cars a smoother approach angle. So in a sense, there are nine spokes.

Meredith calls it an “egg-about” because it’s more elliptical than circular.

Compared to a typical roundabout, traffic patterns at Yarrow Point are unbalanced. Most vehicles would arrive from the westbound highway, then would circle for about 300 degrees to face southbound, toward Clyde Hill or Bellevue. Three side streets, reaching a combined 380 homes or so, would have their own entry points on the ring.

“It’s so overbuilt, it’s ridiculous,” Hirsch said.

One of five crosswalks would channel pedestrians, who might be leaving the parklike lid, across an offramp exiting 520. The DOT contends this is safe, because the new exit ramp includes a bend to slow drivers, and there will be extra signs and beacons.

The existing T-shaped junction has no history of safety hazards, town officials say. As for traffic flow, Meredith said it should attain an “A” grade using either version.

So why a roundabout?

The new highway includes a station in the median for express buses, directly under the lid. So a “kiss and ride” drop-off zone will be provided, with a staircase down to the bus stop.

Meredith said a roundabout works well because drivers can use it to make a sort of U-turn, to reach the kiss-and-ride, instead of turning left against oncoming traffic. This was a reason to choose it, she said.

During the flap two years ago, then-Gov. Chris Gregoire wanted Yarrow Point to put up the $900,000 and build a consensus with neighboring towns, as proof of good faith, according to DOT letters. And the DOT didn’t want to open the floodgates for other requests and rebuttals from nearby, after holding more than 30 briefings with Eastside towns over the years, Meredith said.

Contractors told DOT the costs of a T or roundabout were similar, Meredith said. But now, to scrap the approved roundabout would cost more, she said. This is because utilities and concrete walls have been placed in locations that fit a roundabout.

Fred McConkey, mayor of next-door Hunts Point, said renewed opposition in Yarrow Point probably comes from people nearest the highway, and from people afraid of change. Traffic will flow fine once people get used to the roundabout, as well as a larger one in Hunts Point, he said.

“We spent a great deal of time planning it,” said McConkey, who was worked on 520 group for more than 15 years. “I think it is very well designed. It’s going to work great.”

Meanwhile, a few homeowners have received letters saying DOT will purchase slivers of their property to make room for edges of the roundabout, he said.

Barring a political cataclysm, the roundabout will proceed.

The alternative is more cost, more process and more delay, Meredith said.

A half-mile west, a busier roundabout at Hunts Point will cover the center of a planned lid — farther from houses than the old junction. Many years ago officials envisioned green parks. But in forums, “the only thing people cared about was traffic, getting home,” thus more road lanes on the lids, said McConkey.

The giant Hunts Point rotary offers not one lane but two on the circle, placing it in a league with the famed rotaries of Boston.